Oxygen Carrying Capacity 2

Question 1

How Much O2 can HB Carry?

Answer 1

HB can carry 1.34 mL O2
- 1 molecule HB = 4 molecules of O2

Question 2

O2 Carrying Capacity of HB

Answer 2

actual o2 carried/ total o2 that can be carried
0/4 = desaturated
2/4 = partially saturated
3/4 = partially saturated
4/4 = fully saturated

Question 3

High PO2

Answer 3

strong affinity
- 100mmHg arterial blood
- rbc picks up O2

Question 4

Low PO2

Answer 4

weak affinity
- 40 (rest) and 0 (exercise)
- lowest at skeletal muscle

Question 5

Oxyhaemoglobin Dissociation Curve (ODC)

Answer 5

protective mechanism to ensure adequate saturated O2% despite fluctuations in atmospheric O2 (plateau)
- increased % of HB saturation = increased PO2

Question 6

ODC Exercise Application

Answer 6

• decline after 40 mmHg (PO2 of muscle is 40 mmHg)
• sharp decline means that HB is unloading O2 into tissue

Question 7

what affects HB Affinity

Answer 7

• blood pH and temperature

Question 7

Bohr Effect

Answer 7

more acidic pH (exercise) = HBreleases O2 more readily
(increased saturated O2%)

Question 8

Effect of Temperature

Answer 8

increased temperature = increased O2 release (due to warmer temperatures inducing less HBO2 binding sites)

Question 8

2,3 Diphosphoglycerate

Answer 8

by-product of anaerobic glycolysis
- lowers HBO2 binding and greater O2 release (helps O2 release from haemoglobin)

Question 8

2,3 DPG Causes

Answer 8

• higher altitude = higher 2,3 DPG
• higher in athletes or females?
• increased by HGH, hyperthermia, catecholamine release and acidosis